Temperature when measuring climate change this is a primary and can be measured or reconstructed for the Earth's surface, and sea surface temperature (SST). Precipitation (rainfall, snowfall etc) offers another indicator of relative climate variation and may include humidity or water balance, and water quality.

Climate measurement standards ensure compatibility for observing methodology which in turn increases the quality data. Standards provide a critical level playing field….the same bench mark from which we can all measure so that data are collected consistently through the years and between stations.

In the real world, standards cannot be fully met all of the time (e.g., instrument exposure). Every site has factors which bias the measurements in some way or another. A good precipitation site is not necessarily a good temperature location, is not necessarily a good wind location,…etc. However, standards do provide a critical, compatible, framework for the collection of the measurements.